Switching from high-efficacy lipid-lowering therapies to simvastatin and low-density lipoprotein cholesterol goal attainment in coronary heart disease/coronary heart disease-equivalent patients

Effects of atorvastatin and simvastatin on oxidative stress in diet-induced hyperhomocysteinemia in Wistar albino rats: a comparative study

Considering the well-known antioxidant properties of statins, it seems important to assess their impact on major markers of oxidative stress (superoxide anion radical, nitric oxide, and index of lipid peroxidation) to compare the antioxidative potentials of atorvastatin and simvastatin during the different degrees of hyperhomocysteinemia (HHcy) in rats. This study was conducted on adult male Wistar albino rats (n = 90; 4 weeks old; 100 ± 15 g body mass) in which HHcy was achieved by dietary manipulation. For 4 weeks, the animals were fed with one of the following diets: standard rodent chow, diet enriched in methionine with no deficiency in B vitamins (folic acid, B6, and B12), or diet enriched in methionine and deficient in B vitamins (folic acid, B6, and B12). At the same time, animals were treated with atorvastatin at doses of 3 mg/kg/day i.p. or simvastatin at doses of 5 mg/kg/day i.p. Levels of superoxide anion radical and TBARS were significantly decreased by administration of simvastatin in normal and high-homocysteine (Hcy) groups (p < 0.05). At 4 weeks after feeding with purified diets, the concentrations of the GSH, CAT, and SOD antioxidants were significantly affected among all groups (p < 0.05). Our results indicated that statin therapy had variable effects on the redox status in hyperhomocysteinemic rats, and simvastatin demonstrated stronger antioxidant effects than did atorvastatin.

Impact of treatment with rosuvastatin and atorvastatin on cardiovascular outcomes: evidence from the Archimedes-simulated clinical trials

Objective

No clinical trials have been conducted to directly compare the effect of the two high-intensity statins, rosuvastatin and atorvastatin, on cardiovascular outcomes. However, three such trials have been computer-simulated using the Archimedes model, an individual-based simulation of human physiology and behaviors, treatment interventions, and health care systems. The results are reviewed here.

Methods

The first simulated trial assessed clinical outcomes in patients receiving available doses of the two drugs. The second assessed the impact of initial treatment decisions, while the third assessed the effect of switching from rosuvastatin to atorvastatin.

Results

In the first simulated trial, treatment with rosuvastatin was estimated to result in greater reductions than treatment with atorvastatin in major adverse cardiac event (MACE) rates at 5 years and 20 years at all doses examined (relative risk [RR]: 0.897, 0.888, and 0.930 at 5 years for rosuvastatin 20 mg vs atorvastatin 40 mg, rosuvastatin 40 mg vs atorvastatin 80 mg, and rosuvastatin 20 mg vs atorvastatin 80 mg, respectively; all P<0.05). In the second simulated trial, outcomes were significantly better in patients initially prescribed rosuvastatin than in those initially prescribed atorvastatin (RR of MACE at 5 years: 0.918; P<0.001). In the third simulated trial, risk of MACE was significantly greater in patients switching from rosuvastatin to atorvastatin than in those remaining on rosuvastatin (RR at 5 years: 1.109; P<0.001).

Conclusion

The results of these simulated clinical trials suggest improved outcomes among patients receiving rosuvastatin relative to patients receiving atorvastatin in various clinical settings.

Impact of Switching From High-Efficacy Lipid-Lowering Therapies to Generic Simvastatin on LDL-C Levels and LDL-C Goal Attainment Among High-Risk Primary and Secondary Prevention Populations in the United Kingdom

PURPOSE

High cholesterol, especially high low-density lipoprotein cholesterol (LDL-C), is an important risk factor for cardiovascular disease (CVD) morbidity/mortality. Switching from high-efficacy lipid-lowering therapies (HETs) to simvastatin might lead to sub-optimal control of LDL-C. Our objective was to evaluate the impact of switching from HETs to generic simvastatin on LDL-C levels and LDL-C goal attainment among the high-risk primary and secondary prevention populations in the United Kingdom.

METHODS

This retrospective cohort study was conducted using Clinical Practice Research Datalink database. Included were individuals with more than 2 months of prescriptions of the following HETs between August 1, 2004 and December 31, 2008: simvastatin/ezetimibe fixed dose (S/E), simvastatin and ezetimibe co-administration (S+E), atorvastatin and ezetimibe co-administration (A+E), rosuvastatin and ezetimibe co-administration (R+E), rosuvastatin monotherapy, and atorvastatin monotherapy. For each baseline HET, we used analysis of covariance (ANCOVA) to estimate the least squares mean (LSM) difference in the percentage change from baseline in LDL-C between switchers and non-switchers, and logistic regression to estimate the odds ratio of attaining the LDL-C goal (<3 mmol/L for primary prevention and <2 mmol/L for secondary prevention, by JBS2) at follow-up. Propensity score adjusted analyses were conducted to reduce selection bias.

FINDINGS

30,148 patients met the eligibility criteria with 83.8% received atorvastatin, 9.5% rosuvastatin and 2.6% S/E and S+E combined. 89.1% of patients switching from atorvastatin switched to an equivalent or higher dose of simvastatin (dose equivalency was determined by relative efficacy of one statin to other statins), while 100% of those switching from simvastatin/ezetimibe and 96.8% of those switching from rosuvastatin switched to lower than equivalent dose of simvastatin. Compared to non-switchers, the adjusted least squares mean differences in the percentage change in LDL-C levels from baseline were 18.74% (p = 0.0003), 16.73% (p < 0.0001), and -0.11% (p = 0.9044) when switching from simvastatin/ezetimibe, rosuvastatin, and atorvastatin, respectively. The odds of LDL-C goal attainment at follow-up among switchers from simvastatin/ezetimibe, rosuvastatin, and atorvastatin were 0.40 (95% CI: 0.23-0.70), 0.36 (95% CI: 0.26-0.51) and 1.03 (95% CI: 0.92-1.15) relative to non-switchers respectively.

IMPLICATIONS

Among the high risk CVD population in UK, switching to simvastatin from HET, especially rosuvastatin and simvastatin/ezetimibe, resulted in an increase in LDL-C levels and lower goal attainment. These historical data reinforce the appropriateness of the changes in the new Joint British Guideline (JBS3) which no longer recommends starting simvastatin 40 mg.

Predictors of statin compliance after switching from branded to generic agents among managed-care beneficiaries

OBJECTIVES

To identify patient demographics and characteristics associated with compliance to statin therapy after switching from branded to generic agents

DESIGN

Retrospective cohort study using electronic health records and pharmacy claims data from Sutter Health's ambulatory-care medical network

PATIENTS

Managed-care beneficiaries, ≥ 18 years of age, who were switched from branded to generic statins between 1 January 2003 and 31 December 2012 MAIN MEASURES: Compliance was calculated as days of therapy dispensed divided by days from first to last generic prescription fill over 6 months, and was defined as a medication possession ratio ≥ 0.80. We used multivariable logistic regression to assess factors associated with compliance. Adjusted ORs and 95% CI were generated.

KEY RESULTS

We identified 5,156 patients who were switched from branded to generic statins; 73% of patients were compliant in the 6 months after switching. After statistical adjustment, higher compliance was associated with each 10-year increase in age (OR: 1.13; 95% CI: 1.07, 1.19; p < 0.001), receipt of a generic statin equivalent in potency to the prior branded statin (OR: 1.41; 95% CI: 1.16, 1.70; p < 0.001), and compliance with prior branded statin (OR: 4.68; 95% CI: 4.07, 5.39; p < 0.001). Lower compliance was seen among Hispanic patients compared to non-Hispanic white patients (OR: 0.68; 95% CI: 0.52, 0.91; p = 0.009). Also, a switch to a higher potency generic statin, regardless of prior dose/potency, was negatively associated with compliance after switching (OR: 0.87; 95% CI: 0.80, 0.94; p = 0.001).

CONCLUSIONS

The majority of patients switched from branded to generic agents were compliant with therapy in the first 6 months after switching. The potential for non-compliance to generic statin therapy, particularly among younger or Hispanic patients or when dose/potency changes are made, should be considered prior to switching. For these patients, counseling or close monitoring may be required to optimize generic interchange.

Limitations of real-world treatment with atorvastatin monotherapy for lowering LDL-C in high-risk cardiovascular patients in the US

BACKGROUND

Guidelines endorse statin therapy for lowering low-density lipoprotein cholesterol (LDL-C) to recommended levels, in patients with cardiovascular disease (CVD) risk, if needed, after lifestyle changes. Atorvastatin is a common statin with greater LDL-C lowering efficacy than most other statins; its availability in generic form will likely increase its use. This study assessed attainment of guideline-recommended LDL-C levels in high-risk CVD patients treated with atorvastatin monotherapy.

METHODS

Analyses of two retrospective US cohorts of patients who received a prescription for atorvastatin monotherapy between January 1, 2008 and December 31, 2010 (index date defined as first prescription date) in the GE Centricity Electronic Medical Record (EMR) (N=10,693) and Humana Medicare (N=16,798) databases. Eligible patients were ≥18 years, diagnosed with coronary heart disease or atherosclerotic vascular disease, with ≥1 LDL-C measurement between 3 months and 1 year postindex date, and continuously enrolled for 1 year prior to and following the index date.

RESULTS

Of the eligible patients, 21.8%, 29.6%, 29.9%, and 18.7% (GE Centricity EMR) and 25.4%, 32.9%, 27.8%, and 14.0% (Humana Medicare) received 10, 20, 40, and 80 mg doses of atorvastatin, respectively. The mean ± standard deviation (SD) follow-up LDL-C levels were 2.1±0.8 mmol/L (83±30 mg/dL) and 2.3±0.8 mmol/L (88±31 mg/dL) for the GE Centricity EMR and Humana Medicare cohorts, respectively. Regardless of dose, only 28.3%-34.8% of patients had LDL-C levels <1.8 mmol/L (<70 mg/dL), and 72.0%-78.0% achieved LDL-C <2.6 mmol/L (<100 mg/dL) in both cohorts. As many as 41% and 13% of patients had LDL-C levels ≥0.5 mmol/L (≥20 mg/dL) above LDL-C 1.8 mmol/L (70 mg/dL) and 2.6 mmol/L (100 mg/dL), respectively, in both cohorts; these percentages were generally similar across atorvastatin doses.

CONCLUSION

In this real-world US setting, a large number of high-risk CVD patients did not attain guideline-recommended LDL-C levels with atorvastatin monotherapy. More than 65% of the patients had LDL-C levels >1.8 mmol/L (>70 mg/dL), and of these, 30%-40% had LDL-C levels ≥0.5 mmol/L (≥20 mg/dL) above this, regardless of dose. This suggests that more effective lipid-lowering strategies, such as statin uptitration, switching to a higher efficacy statin, and/or combination therapy, may be required to achieve optimal LDL-C lowering in high-risk patients.

Changes in LDL-C levels and goal attainment associated with addition of ezetimibe to simvastatin, atorvastatin, or rosuvastatin compared with titrating statin monotherapy

Background

Many high-risk coronary heart disease (CHD) patients on statin monotherapy do not achieve guideline-recommended low-density lipoprotein cholesterol (LDL-C) goals, and combination lipid-lowering therapy may be considered for these individuals. The effect of adding ezetimibe to simvastatin, atorvastatin, or rosuvastatin therapy versus titrating these statins on LDL-C changes and goal attainment in CHD or CHD risk-equivalent patients was assessed in a large, managed-care database in the US.

Methods

Eligible patients (n = 17,830), initially on statin monotherapy who were ≥18 years with baseline and follow-up LDL-C values, no concomitant use of other lipid-lowering therapy, and on lipid-lowering therapy for ≥42 days, were identified between November 1, 2002 and September 30, 2009. The percent change from baseline in LDL-C levels and the odds ratios for attainment of LDL-C <1.8 and <2.6 mmol/L (70 and 100 mg/dL) were estimated using an analysis of covariance and logistic regression, respectively, adjusted for various baseline factors.

Results

LDL-C reductions from baseline and goal attainment improved substantially in patients treated with ezetimibe added onto simvastatin, atorvastatin, or rosuvastatin therapy (n = 2,312) versus those (n = 13,053) who titrated these statins. In multivariable models, percent change from baseline in LDL-C was −13.1% to −14.8% greater for those who added ezetimibe onto simvastatin, atorvastatin, or rosuvastatin versus those who titrated. The odds of attaining LDL-C <1.8 and <2.6 mmol/L (70 and 100 mg/dL) increased by 2.6–3.2-fold and 2.5–3.1-fold, respectively, in patients who added ezetimibe onto simvastatin, atorvastatin, or rosuvastatin versus titrating statins.

Conclusion

CHD/CHD risk-equivalent patients in a large US managed-care database, who added ezetimibe onto simvastatin, atorvastatin, or rosuvastatin, had greater LDL-C reductions and goal attainment than those who uptitrated these statin therapies. Our study suggests that high-risk CHD patients in need of more intensive LDL-C lowering therapy may benefit by adding ezetimibe onto statin therapy.

Therapeutic practice patterns related to statin potency and ezetimibe/simvastatin combination therapies in lowering LDL-C in patients with high-risk cardiovascular disease

BACKGROUND

Statin combination therapy and statin uptitration have been shown to be efficacious in low-density lipoprotein cholesterol (LDL-C) lowering and are recommended for patients with high-risk coronary heart disease (CHD) who do not reach guideline-endorsed LDL-C goals on statin monotherapy.

OBJECTIVE

This analysis evaluated treatment practice patterns and LDL-C lowering for patients with CHD/CHD risk equivalent on statin monotherapy in a real-world practice setting in the United States.

METHODS

In this retrospective, observational study, patients with CHD/CHD risk equivalent on statin therapy were identified during 2004 to 2008 in a US managed care database. Prescribing patterns and effect of switching from statin monotherapy to combination ezetimibe/simvastatin therapy vs uptitration to higher statin dose/potency level and no change from initial statin potency on LDL-C lowering were assessed. Percentage of change from baseline in LDL-C levels and odds ratios for LDL-C goal attainment were estimated with analyses of covariance and logistic regression.

RESULTS

Of 27,919 eligible patients on statin therapy, 2671 (9.6%) switched to ezetimibe/simvastatin therapy, 11,035 (39.5%) uptitrated statins, and 14,213 (50.9%) remained on the same statin monotherapy. LDL-C reduction from baseline and attainment of LDL-C <100 and <70 mg/dL were substantially greater for patients who switched to ezetimibe/simvastatin therapy (-24.0%, 81.2%, and 35.2%, respectively) than for patients who titrated (-9.6%, 68.0%, and 18.4%, respectively) or remained on initial statin therapy (4.9%, 72.2%, and 23.7%, respectively). The odds ratios for attainment of LDL-C <100 and <70 mg/dL were also higher for patients who switched than for patients who uptitrated and had no therapy change than for patients who titrated vs no therapy change. Similarly, among a subgroup of patients not at LDL-C <100 mg/dL on baseline therapy, attainment of LDL-C <100 and <70 mg/dL was greater for patients who switched than for statin uptitration vs no change, as well as for patients who uptritrated statins vs no therapy change.

CONCLUSION

In this study, LDL-C lowering and goal attainment rates improved substantially for patients with high-risk CHD on statin monotherapy who switched to combination ezetimibe/statin or uptitrated their statin therapies; however, approximately one-third of these patients still did not attain the optional recommended LDL-C goal of <70 mg/dL. Moreover, these higher efficacy lipid-lowering therapies were infrequently prescribed, indicating the need for further assessment of barriers to LDL-C goal attainment in actual practice settings.